Recently, the semiconductor industry has developed an ultra-fine technique having a pattern of several to several tens of nanometers in size. Such ultrafine technique essentially needs effective lithographic techniques.
The typical lithographic technique includes providing a material layer on a semiconductor substrate; coating a photoresist layer thereon; exposing and developing the same to provide a photoresist pattern; and etching the material layer using the photoresist pattern as a mask.
Nowadays, when small-sizing the pattern to be formed, it is difficult to provide a fine pattern having an excellent profile by only the above-mentioned typical lithographic technique. Accordingly, a layer, called a hardmask layer, may be formed between the material layer and the photoresist layer to provide a fine pattern.
The hardmask layer plays the role of an intermediate layer for transferring the fine pattern of photoresist to the material layer through a selective etching process. Accordingly, the hardmask layer is required to have characteristics such as heat resistance and etch resistance, and the like during the multiple etching processes.
On the other hand, it has been recently suggested to form a hardmask layer by a spin-on coating method instead of chemical vapor deposition. The spin-on coating method requires a hardmask composition having dissolubility for a solvent.
The dissolubility is related to gap-filling characteristics for filling a hardmask composition in gaps between patterns, as well as planarization characteristics. As the molecular weight of a monomer for a hardmask composition becomes lower, the gap-filling characteristics become better.
However, when the monomer for the hardmask composition has a molecular weight, out-gas may be generated during a high temperature process.